InChI=1S/C20H20O5/c1-11(2)7-8-13-15(22)9-16(23)19-17(24)10-18(25-20(13)19)12-5-3-4-6-14(12)21/h3-7,9,18,21-23H,8,10H2,1-2H3/t18-/m0/s1